林口長庚紀念醫院 加護腎臟科 / 陳永昌
Outline
Introduction
CRRT Nomenclature
Applications for CRRT
Fluid Management in CRRT
Clinical Aspects
Evidence Based Medicine
Conclusions
AKI in ICUs
In ICUs, acute kidney injury (AKI) frequently occurs in patients with medical or surgical complications and multiorgan failure
Worse prognosis
Standard intermittent renal replacement (IHD) treatments are often contraindicated
RIFLE Classification
GFR criteria Urine output criteria
Risk Increase SCr x 1.5 or GFR decrease >25%
UO < 0.5ml/kg/h x 6 hr
Injury Increase SCr x 2 or GFR decrease >50%
UO < 0.5ml/kg/h x 12 hr
Failure Increase SCr x 3 or GFR decrease >75% or
SCr > 4 mg/dl
UO < 0.3ml/kg/h x 24 hr or anuria x 12 hr
Loss Complete loss of kidney function > 4 weeksESRD End stage renal disease (> 3 months)
(Bellomo R et. al. Critcal Care 2004)
Contraindication to Hemodialysis
Hemodynamic instability (hypotension, presence of significant cardiovascular disease)
Lack of access to circulation
Lack of highly trained staff and/or equipment
Indication and Timing of Dialysis for AKI Renal Replacement vs. Renal Support
Renal replacement Renal support
Purpose
Timing of intervention
Indications for dialysis
Dialysis dose
Replace renal function
Based on level
biochemical markers
Narrow
Extrapolated from ESRD
Support other organs
Based on individual
need
Broad
Targeted for overall support
CRRT vs. IHD
CRRT IHD
Hemodynamic stabilityFluid removalDialysis efficiencyAnticoagulationPatient mobilizationSpecialty personnelDrug dosing/deliveryVolume restriction
StableSlow, gentle, completeLow efficiency, long timeFrequently necessaryPossible PerhapsEasierMinimal
UnstableRapid, harsh, incompleteHigh efficiecy, short timeZero heparin possiblePossibleDefinitelyDifficultSignificant
Continuous Renal Replacement Therapy (CRRT)
CAVH: Continuous arteriovenous hemofiltration
CAVHD: Continuous arteriovenous hemodialysis
CAVHDF: Continuous arteriovenous hemodiafiltration
CVVH: Continuous venovenous hemofiltration
CVVHD: Continuous venovenous hemodialysis
CVVHDF: Continuous venovenous hemodiafiltration
AVSCUF: Arteriovenous slow continuous ultralfiltration
VVSCUF: Venovenous slow continuous ultralfiltration
VX
X
CRRT: AV vs. VV
Arteriovenous therapies (AV) Technique simplicity Required large-bore arterial catheter Blood flow dependent on MAP
Venovenous therapies (VV) No arterial line Pump-assisted Blood flow independent of blood pressure
CGMH CRRT Order
1. Diagnosis2. CVVH Solution A 3000 cc + 15% KCl __ cc IVF (500~ cc/hr)3. CVVH Solution B 3000 cc + 7% NaHCO3 240 cc IVF(500~cc/hr)4. Record I/O Q1h and Keep I/O _____5. Check: BUN,Cr, Na, K, Cl, Ca, P QD; Mg QW1,46. Blood flow 120ml/min7. Check ACT Q6h and Keep ACT at 200~250 secP.S. 15% KCl 6 cc/3L
7.5 cc/3L9 cc/3L10.5 cc/3L12 cc/3L
2.012 meq/L K2.515 meq/L K3.018 meq/L K3.521 meq/L K4.024 meq/L K
Multi-mode continuous renal replacement machine
Applications for CRRT (1)
Renal application (renal replacement and renal support)Acute renal failure (specifically complicated ARF with multiple organ failure)
Oligouric ARF needs large amount of fluid or nutrition
Fluid overloading
An alternative to HD in the mass casualty situation
Electrolytes and acid base disturbance
Applications for CRRT (2)
Non-renal application Hepatic failure complicated with hepatic coma Congestive heart failure refractory to diuretics Overhydration during & after cardiac surgery (CPB & after) Sepsis Life-threatening hyperthermia Hemofiltration for poisoning (lactic acidosis, lithium poisoning) Cytokine removal: Acute respiratory distress syndrome Chemofiltration, chemoperfusion
Potential Complications of CRRT
Technical Clinical
Vascular access malfunction
Circuit clotting
Circuit explosion
Catheter and circuit kinking
Insufficient blood flow
Line-catheter disconnection
Fluid balance errors
Loss of efficiency
Bleeding, Hematomas
Thrombosis
Infection and sepsis
Allergic reactions
Hypothermia
Nutrient losses
Insufficient blood purification
Hypotension, arrhythmia
Fluid Removal vs. Fluid Regulation
Fluid removal Fluid regulation Normal kidney
IHD
PD
CRRT
+++++++++++
++++--+++
Hemofiltration
(CAVH, CVVH)
Hemodialysis
(CAVHD, CVVHD)
Hemodiafiltration
(CAVHDF, CVVHDF)
Fluid Convection Convection ConvectionSolute Convection Diffusion Convection +
DiffusionBack transport None Possible Possible
Fluid and Solute Removal in CRRT
Components of Fluid Regulation
Fluid Balance
Fluid composition
Electrolyte and Acid Base homeostasis
Nutritional balance
Temperature control
Volume Adjustment for Fluid Management
Level 1: Ultrafiltrate volume limited to match anticipated needs for fluid balance over 8-24 hours. Limited replacement fluid.
Level 2: Ultrafiltrate volume greater than hourly intake. Net fluid balance achieved by hourly replacement fluid administration.
Level 3: Ultrafiltrate volume adjusted greater than hourly intake. Net fluid balance targeted to achieve specific hemodynamic parameters eg. CVP, PAWA, MAP.
Sliding Scale for Volume Adjustment
Desired volume change (ml/hr)
PAWP < 6
PAWP 6-8
PAWP 9-11
PAWP 12-14
PAWP 15-17
PAWP 18-20
PAWP 21-22
PAWP >22
+ 175 ml and notify nephrologist
+ 125 ml
+ 75 ml
Zero balance
50 ml
75 ml
100 ml
125 ml and notify nephrologist
Electrolyte and Acid Base Derangements
Continuous therapies can be used to correct water and electrolyte imbalances
Hypo-hypernatremia can be corrected not only achieving a normal plasma sodium concentration, but also by restoring the normal body sodium content
Hyperkalemia can also be corrected: the efficiency of continuous arteriovenous and venovenous hemofiltration in removing potassium is low
AKI in Neonates
Continuous arteriovenous hemofiltration is especially useful in the treatment of acute renal failure in neonates and small babies (Ronco et al. 1984, 1986)
CRRT as a successful bridge to liver transplantation should be considered in children with unrelenting hyperammonemia not amenable to routine medical therapy (Chen CY et al. 2000)
Treatment of Multiple Organ Dysfunction and Sepsis with CRRT
Eicosanoids, cytokines (tumor necrosis factor and interleukins such as IL-1, IL-6, and IL-8), endothelin, and platelet-activating factor may all contribute to the reduction of renal blood flow and GFR during sepsis
ARF cannot be treated effectively unless the underlying problems are resolved
CVVH using the high-permeability membranes allows extraction of significant quantities of circulating macromolecules (MW 30 kDa)
CRRT of AKI in Burns Patients
CRRT may maintain a good uremic control for severely catabolic burns patients with multiorgan dysfunction Treatment is possible despite cardiovascular instability and total parenteral nutrition can be givenCAVHD appears to give somewhat better uremic control, but the difference in mortality is not significant Large burns, pulmonary burns and septicemia seems to be bad prognostic signs (Leblanc et al. 1999)
Advantage of CRRT for Nutritional Support
Fluid restrictions are removed Electrolyte overload is avoidedHyperosmolar nutrition solutions are safeCRRT result in a cumulative Kt/V or small solute removal rate equivalent or superior to conventional intermittent 4 hours HD IHD daily X 4 hr: Kt/V weekly 7.5 IHD X three sessions /week: Kt/V weekly 3.2 CAVHD: Kt/V weekly 6.2 CVVHD: Kt/V weekly 8.0 (Leblanc M. et al. Semin Dial 1995)CRRT provide adequate clearance of nitrogenous compounds with the avoidance of repeatedly high peak serum nitrogen values (Clark WR et al. JASN 1994)
Regional Chemotherapy plus Hemofiltration vs. Hemoperfusion
Regional intra-arterial chemotherapy: drug delivery 1.5~2 x systemic dose
Regional chemotherapy plus hemofiltration: drug delivery 3~4 x systemic dose
Regional chemotherapy plus hemoperfusion: drug delivery 5~8 x systemic dose
Ability to overcome drug delivery problems and resistance
Improves survival for HCC, pancreatic cancers, and hepatic metastasis colorectal cancer (Muchmore et al. 1999)
CRRT in Liver Support
Requirements for liver supportDetoxificationFluid regulationAcid-Base and electrolyte homeostasisIndications of CRRT support Combines renal and liver failure Liver transplant Mx of complications of decompensated liver disease
– Ascites– Encephalopathy
Post Cardiac Surgery AKI
Intra-operative support and post-operative problems Oxygenator membranes and cytokine generation Blood tubing and extraction of plasticizers (DEHP) Prolonged bypass time and hemodynamic consequences
Application of aggressive ultrafiltration in the cardiac support of children and outcome improvement
Dialysis variants added to extracorporeal cardiac support system VAD and support ECMO and support IABP and support
(Lin CY, Chen YC, Fang JT et al. JN 2008)
Evidence Based Medicine (1)
Optimal way to deliver CRRT does not existAcute Dialysis Quality Initiative (ADQI) aims at establishing an evidence-based appraisal and set of consensus recommendations to standardize care and direct further researchhttp://www.ADQI.net
Evidence Based Medicine (2)
Levels of EvidenceLevel I: Randomized trials with low false positive () and low false negative () error (i.e. high power)
Level II: Randomized trials with high error or low power
Level III: Non-randomized concurrent cohort studies
Level IV: Non-randomized historic cohort studies
Level V: Case series, case reports, expert opinion
Evidence Based Medicine (3)
Grades of RecommendationsGrade A: Supported by at least 2 level I studies
Grade B: Supported by only 1 level I study
Grade C: Supported level II studies
Grade D: Supported by at least 1 level III study
Grade E: Supported by only level IV or V studies
Evidence Based Medicine (4)
CRRT use in a variety of non-ARF conditions including intoxication with dialyzable/filterable drugs or toxins, cardiac failure, ARDS, and pediatric cardiac surgery or sepsis and systemic inflammationInsufficient evidence to recommend the use of CRRT for non-ARF indications outside clinical investigation (Grade E)CRRT use may be advantageous in the management of ICU patients with ARF (Grade E)CRRT is recommended over IHD for patients with AKI who have, or are at risk for, cerebral edema (Grade C)
CVVH Dose (1)
(Ronco C et al. Lancet 2000)
CVVH Dose (2)
CVVH Dose (3)
Intensive vs. Less-Intensive Strategy (1)
(Palevsky PM et al. NEJM 2008)
Intensive vs. Less-Intensive Strategy (2)
Intensive vs. Less-Intensive Strategy (3)
CVVHDF vs. CVVH (1)
(Saudan P et al. KI 2006)
CVVHDF vs. CVVH (2)
CVVHDF vs. CVVH (3)
p=0.0005
CRRT vs. IHD (1)
(Tonelli M et al. AJKD 2002)
CRRT vs. IHD (2)
(Vinsonneau C et al. Lancet 2006)
CRRT vs. IHD (3)
CRRT vs. IHD (4)
CRRT vs. IHD (5)
B.E.S.T. Kidney Investigators
(Uchino S et al. ICM 2007)
Less Chronic Kidney Disease in CRRT
(Bell M et al. ICM 2007)
Conclusions
CRRT are safe, simple, effective, and well tolerated in the management of patients with multiple organ failure and acute renal failure Maintenance of water, and electrolyte balance Removal of metabolic waste products Removal of inflammatory mediators of MOSF Facilitate full nutrition support The treatment of choice in critically ill patients with acute renal failure No particular form of CRRT has yet shown to be superior of survival
Scheme for Selection of a Renal Replacement Therapy in ICUs: Patient-
Center ApproachingRenal Failure requiring renal replacement therapy
Uni-organ failure Multi-organ failure
Intermittent Hemodynamically Hemodynamically hemodialysis stable unstable
Main problems: Main problems: CRRT
biochemical/uremia fluid overload or cytokines
Intermittent Hemodialysis CRRT (EDD, SLED)
IHDIntolerance
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